Boaduo N.K.K., Katerere D., Eloff J.N., Naidoo V.
Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Onderstepoort, South Africa; South African Medical Research Council, Cape Town, South Africa; Department of Paraclinical Sciences, University of Pretoria, South Africa; Faculty of Veterinary Science, University of Pretoria Biomedical Research Centre, University of Pretoria, Private Bag X04, Ondersterpoort 0110, South Africa
Boaduo, N.K.K., Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Onderstepoort, South Africa; Katerere, D., South African Medical Research Council, Cape Town, South Africa; Eloff, J.N., Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Onderstepoort, South Africa; Naidoo, V., Department of Paraclinical Sciences, University of Pretoria, South Africa, Faculty of Veterinary Science, University of Pretoria Biomedical Research Centre, University of Pretoria, Private Bag X04, Ondersterpoort 0110, South Africa
Context: Numerous plants are used by the local communities of South Africa for the treatment and management of type II diabetes. Objectives: For this study, we undertook a survey of the plants sold for the management of diabetes in the town of Newcastle, South Africa. Identified plants were subsequently evaluated for their in vitro antidiabetic activity. Materials and methods: Plants were identified through an interview with a herbalist at the market. Antidiabetic activity of extracts of purchased plants was evaluated using in vitro α-amylase and α-glucosidase activity, as well as islets of Langerhans excretory activity. Results: Senna alexandrina Mill. (Fabaceae), Cymbopogon citrates Stapf. (Poaceae), Cucurbita pepo L. (Cucuribitaceae), Nuxia floribunda Benth. (Stilbaceae), Hypoxis hemerocallidea Fisch. and Mey (Hypoxidaceae), and Cinnamomum cassia Blume (Lauraceae) were identified. The hexane extract of S. alexandrina (EC50=0.083mg/ml), ethyl acetate extract of H. hemerocallidea (EC50=0.29mg/ml), and methanol extracts of Cymbopogon citratus (EC50=0.31mg/ml) and Cinnamomum cassia (EC50=0.12mg/ml) had the highest α-amylase inhibitory activity, albeit lower than acarbose (EC50=0.50mg/ml). All the plants had good α-glucosidase inhibitory activity (>50%) with the exception of some methanol (Cinnamomum cassia, N. floribunda, and Cymbopogon citratus) and acetone extracts (Cucurbita pepo and N. floribunda). Only the H. hemerocallidea acetone extract had an insulin stimulatory effect (2.5U/ml at 8μg/ml). Conclusion: All the evaluated plants demonstrated inhibitory activity against the specific GIT enzyme systems evaluated. Only H. hemerocallidea had insulin secretory activity, adding evidence to the traditional use of these purchased plants in the management of the type II diabetic post-prandial hyperglycemia. © 2014 Informa Healthcare USA, Inc. All rights reserved.
acarbose; alpha glucosidase; amylase; antidiabetic agent; Cinnamomum cassia extract; Cucurbita pepo extract; Cymbopogon citrates extract; glibenclamide; Hypoxis hemerocallidea extract; insulin; Nuxia floribunda extract; plant extract; Senna alexandrina extract; unclassified drug; antidiabetic agent; plant extract; animal cell; antidiabetic activity; article; controlled study; Cucurbita pepo; Cymbopogon citrates; diabetes mellitus; drug mechanism; drug screening; enzyme activity; enzyme inhibition; Hypoxis hemerocallidea; in vitro study; medicinal plant; nonhuman; Nuxia floribunda; pancreas islet; rat; Senna alexandrina; South Africa; animal; blood; cell culture; Diabetes Mellitus, Type 2; drug effects; isolation and purification; medicinal plant; metabolism; procedures; Sprague Dawley rat; treatment outcome; Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Hypoglycemic Agents; Islets of Langerhans; Plant Extracts; Plants, Medicinal; Rats; Rats, Sprague-Dawley; South Africa; Treatment Outcome